CAC vs LTV: The Math That Decides If Your Paid Traffic Is Profitable
A common mistake in paid traffic is optimizing only to lower CAC (Customer Acquisition Cost) — the amount spent on ads divided by the number of customers acquired. It seems logical: lower CAC, better campaign. But that metric alone doesn't say whether the campaign is actually profitable.
The other side of the equation is LTV (Lifetime Value): how much revenue that customer generates across the entire relationship with the company, not just the first purchase. A low CAC with a low LTV still loses money — what actually matters is the ratio between the two.
The practical rule used by people who work with paid acquisition is simple: LTV needs to be at least 3 times higher than CAC. Below that ratio, each new sale ends up costing more, in the long run, than it returns over the customer's lifetime — even if the campaign looks cheap when you only look at cost per click.
This changes the question worth asking before increasing ad budget: it's not "is my CAC low?", it's "does my LTV cover my CAC with enough margin to grow safely?"